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濂嬫枟娌℃湁缁堢偣浠讳綍鏃跺�欓兘鏄竴涓捣鐐?/p>
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淇¤揪
鍒濅腑鏁板璇曞嵎
22.1.2
浜屾鍑芥暟
y=ax
2
鐨勫浘璞″拰鎬ц川
瑕佺偣鎰熺煡
1
浜屾鍑芥暟
y=ax
2
鐨勫浘璞℃槸
____
锛屽绉拌酱鏄?/p>
____
锛岄《鐐规槸
____.
褰?/p>
a>0
鏃讹紝鎶涚墿绾跨殑寮�鍙ｅ悜
____
锛岄《鐐规槸
鎶涚墿绾跨殑鏈�
____
鐐癸紱褰?/p>
a<0
鏃讹紝鎶涚墿绾跨殑寮�鍙ｅ悜
____
锛岄《鐐规槸鎶涚墿绾跨殑鏈�
____
鐐?/p>
.|a|
瓒婂ぇ锛屾姏鐗╃嚎鐨勫紑鍙?/p>
____.
棰勪範缁冧範
1-1
鎶涚墿绾?/p>
y=-x
2
鐨勫紑鍙ｆ柟鍚?/p>
____
锛岄《鐐瑰潗鏍囨槸
____
锛屽绉拌酱鏄?/p>
____.
瑕佺偣鎰熺煡
2
鍦ㄤ簩娆″嚱鏁?/p>
y=ax
2
(a
鈮?/p>
0)
鍥捐薄涓紝鈶犲綋
a>0
锛?/p>
x>0
鏃讹紝
y
闅?/p>
x
澧炲ぇ鑰?/p>
____
锛?/p>
x<0
鏃讹紝
y
闅?/p>
x
澧炲ぇ鑰?/p>
____
锛?/p>
褰?/p>
x=0
鏃讹紝
y
鍙栨渶
____
鍊兼槸
0
锛涒憽褰?/p>
a<0
锛?/p>
x>0
鏃讹紝
y
闅?/p>
x
澧炲ぇ鑰?/p>
____
锛?/p>
x<0
鏃讹紝
y
闅?/p>
x
澧炲ぇ鑰?/p>
____
锛屽綋
x=0
鏃讹紝
y
鍙?/p>
鏈�
____
鍊兼槸
0.
棰勪範缁冧範
2-1
宸茬煡
A(-1,y
1
),B(-2,y
2
)
閮藉湪鎶涚墿绾?/p>
y=3x
2
涓婏紝鍒?/p>
y
1
銆?/p>
y
2
涔嬮棿鐨勫ぇ灏忓叧绯绘槸
( )
A.y
1
>y
2
B.y
1
=y
2
C.y
1
<y
2
D.
澶у皬鍏崇郴涓嶈兘纭畾